Remove unnecessary top()->document() null check from PluginListChanged.

chrome/renderer/plugins/chrome_plugin_placeholder.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/plugins/chrome_plugin_placeholder.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/command_line.h"
@@ skipping 242 matching lines @@
 
 void ChromePluginPlaceholder::OnCancelledDownloadingPlugin() {
   SetMessage(
       l10n_util::GetStringFUTF16(IDS_PLUGIN_DOWNLOAD_CANCELLED, plugin_name_));
 }
 #endif  // defined(ENABLE_PLUGIN_INSTALLATION)
 
 void ChromePluginPlaceholder::PluginListChanged() {
   if (!GetFrame() || !plugin())
     return;
-  blink::WebDocument document = GetFrame()->top()->document();
-  if (document.isNull())
-    return;
 
   ChromeViewHostMsg_GetPluginInfo_Output output;
   std::string mime_type(GetPluginParams().mimeType.utf8());
   blink::WebString top_origin =
       GetFrame()->top()->getSecurityOrigin().toString();
   render_frame()->Send(
       new ChromeViewHostMsg_GetPluginInfo(routing_id(),
                                           GURL(GetPluginParams().url),
                                           blink::WebStringToGURL(top_origin),
                                           mime_type,
@@ skipping 124 matching lines @@
 
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnablePluginPlaceholderTesting)) {
     builder.SetMethod<void (ChromePluginPlaceholder::*)()>(
         "didFinishIconRepositionForTesting",
         &ChromePluginPlaceholder::DidFinishIconRepositionForTestingCallback);
   }
 
   return builder;
 }